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TPS6593-Q1: 2-phase configuration for AM62A34 with TPS65931211RWERQ1 PMIC

Hitendra Jambukiya
Prodigy 55 points
Part Number: TPS6593-Q1

Tool/software:

Hi TI Team,

We are currently designing a product for an industrial environment with functional safety capabilities, using the AM62A34 processor and TPS65931211RWERQ1 PMIC. Additionally, we are incorporating the DP83867 Ethernet PHY IC for the Ethernet interface.

We have the following queries regarding the power supply configuration for the AM62A34 using the TPS65931211RWERQ1 PMIC:

  1. VCC_CORE Voltage Requirements:
    • Do we need to configure 3-phase (BUCK1 + BUCK2 + BUCK3) with a maximum of 10.5A for the VCC_CORE voltage? According to the AM62A34 datasheet (AM62Ax Maximum Current Ratings), the maximum VCC_CORE current is 6.5A for a 0.75V VCC_CORE supply, plus 200mA for VDDR_CORE, totaling 6.7A.
    • Is a 2-phase configuration providing 7.5A sufficient for the AM62A34 VCC_CORE supply?
    • Can we configure the TPS65931211RWERQ1 to work with the AM62A34 using only a 2-phase configuration (BUCK1 + BUCK2)?
    • If yes, could you please provide the design guidelines for this configuration?
  2. Using BUCK3 for VDD_2V5 of Ethernet PHY DP83867:
    • Can we configure the BUCK3 DC-DC converter to output 2.5V for the Ethernet PHY?
  3. LDO Usage for Ethernet PHY DP83867 1.0V Supply:
    • Is it possible to use any LDO from the PMIC to supply 1.0V to the Ethernet PHY?

We would appreciate your feedback on these queries, particularly ensuring that the functional safety capability is not compromised.

Regards,

  • +1
    TI__Mastermind 20388 points

    Hello Hitendra,

    Hitendra Jambukiya said:
    • Using BUCK3 for VDD_2V5 of Ethernet PHY DP83867:
      • Can we configure the BUCK3 DC-DC converter to output 2.5V for the Ethernet PHY?
    • LDO Usage for Ethernet PHY DP83867 1.0V Supply:
      • Is it possible to use any LDO from the PMIC to supply 1.0V to the Ethernet PHY?

    1.a) Yes, while the maximum maybe for when 0V75 is the set core voltage in dual phase the limitation is 7A, giving only a head room of 500mA assuming that the current being proposed isn't peak, but steady state. If only considering 0V75 core, but if 0V85 this is out of the question.

    1.b) No, from the above it is not, and each rail contributing to the multiphase configuration is adding 3.5A each, hence 7A of working power.

    1.c) No, the settings for phase configuration is part of the static programming that is locked in upon boot.

    1.d) My apologies, at most we can provide a .json for use with the GUI to change the programming, but the validation of the solution would have to be done by you.

    Hitendra Jambukiya said:
    • Using BUCK3 for VDD_2V5 of Ethernet PHY DP83867:
      • Can we configure the BUCK3 DC-DC converter to output 2.5V for the Ethernet PHY?
    • LDO Usage for Ethernet PHY DP83867 1.0V Supply:
      • Is it possible to use any LDO from the PMIC to supply 1.0V to the Ethernet PHY?

    2.a) If the above wasn't a constraint, yes. Another possible solution is adding a discrete PS for the 2.5V Ethernet and trying it to the enable of a power supply or GPIO4

    3.a) Yes, if it meets under the rated current for the LDOs (that aren't on the CORE nets), but here's another solution for either, If you're not going to use VPP(eFUSE) programming this LDO2 may supply what is needed, while the voltage is set at either 3V3 or 1V8, either changing the programming dynamically (with I2C software writes) or by changing the burned in programming from the .json (alot more work logistically from programming to sourcing via our 3rd party)

    The  LDO2 can handle a maximum of 500mA.

    Either way Hitendra, let me know what you would like to know more about or if this is enough.

    BR,

    Nicholas